Pump and dump is detrimental to the cryptocurrency world. I first knew about pump and dump scheme from Pmalek thread where newbies and Jr members answers questions to earn merits. Thanks to him.
Then Op, crypto is not regulated and it has many loopholes through which it can be manipulated. Calling out a few out of thousands for a law suit does not make sense to me and I doubt if you will have a tangible case again them.
The market is all about smartness, the more smart you are the more money you make and the more others lose.
I first understood the concept of pump and dump I believe from most of these masternode coins. The dev team will sell their coins within their discord channel, before listing to the exchange. Once listed, couple of weeks or so, they will start this pump and dump method up until the value of their coin goes down to nothing. And so, they will repeat the cycle again, create, sell, list, and pnd. If you are not a quick thinker, you will end up holding those worthless coins for nothing.